The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Currently, there are a limited number of methods for making sealed, implantable electrical connections. The most commonly used system in neurostimulator devices is the BalSeal SYGNUS® implantable contact system available from Bal Seal Engineering, Inc., or similar solutions. With the BalSeal SYGNUS® implantable contact system, a cylindrical male connector consists of metal contacts along the circumference of the connector. The female connector consists of a series of coiled metal rings that form a diameter smaller than the male connector, separated by silicone as a barrier for moisture. The female connector is typically assembled onto a hermetically-sealed electronics package with electrical feedthroughs, and interconnected using laser welded metal wires. The male connector also contains molded silicone features that enable a physical seal between the female connector inlet and the cylindrical male connector. While this solution is satisfactory for present day cardiac and neuro-stimulation applications with 2-16 channels, it is significantly limited in electrical connection density. Presently available connectors require a male connector of diameter around 1 mm, with a contact density of ˜5 connections per 10 mm. The female connector is even larger in diameter and length than the male connector.
For the next generation of neural interface devices, there is a growing need for a significantly higher number of channels. Current neuro-stimulation devices typically have 2-16 channels, where a standard connector may be acceptable. However, for new devices with hundreds or even thousands or more of independent channels, it is no longer feasible to use bulky electrical connectors. Applications in the neural space which are being investigated at the present time will require literally hundreds of independent channels requiring hundreds of independent connections.